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This question already has an answer here: Adding observer for KVO without pointers using Swift 5 answers What would be the equivalent in swift of this Obj-C code? I'm guessing something with CMutableVoidPointer static void *CapturingStillImageContext = &CapturingStillImageContext; Probably something like this: var CapturingStillImageContext: COpaquePointer = nil withUnsafePointer(&CapturingStillImageContext) { CapturingStillImageContext = COpaquePointer($0) } CMutableVoidPointer isn't available anymore as of Beta 3. Theres UnsafePointer and ConstUnsafePointer - you can declare it this way: let

This code in a GUI application compiles and runs: procedure TForm1.Button1Click(Sender: TObject); begin Self := TForm1.Create(Owner); end; (tested with Delphi 6 and 2009) why is Self writable and not read-only? in which situations could this be useful? Edit: is this also possible in Delphi Prism? (I think yes it is, see here ) Update: Delphi applications/libraries which make use of Self assignment: python4delphi That's not as bad as it could be. I just tested it in Delphi 2009, and it would seem that, while the Self parameter doesn't use const semantics, which you seem to be implying it should

I don't want to write a long text, because it is a short question. PHPUnit tests contain several methods that are static. For example all those \PHPUnit\Framework\Assert::assert*() methods and also the identicalTo , equalTo . My IDE (with IntelliSense/autocompletion) doesn't accept calls with $this , but with self. I have learned that static functions should be called through the class, not an object, so self . What is more correct? $this->assertTrue('test'); or self::assertTrue('test'); ? (And if "$this" is more correct, can you maybe point out why we should not use "self"?) Generally, self

class attrdict(dict): def __init__(self, *args, **kwargs): dict.__init__(self, *args, **kwargs) self.__dict__ = self a = attrdict(x=1, y=2) print a.x, a.y b = attrdict() b.x, b.y = 1, 2 print b.x, b.y Could somebody explain the first four lines in words? I read about classes and methods. But here it seems very confusing. joaquin You are not using positional arguments in your example. So the relevant code is: class attrdict(dict): def __init__(self, **kwargs): dict.__init__(self, **kwargs) self.__dict__ = self In the first line you define class attrdict as a subclass of dict . In the second

I had done a bit of Python long back. I am however moving over to Java now. I wanted to know if there were any differences between the Python "self" method and Java "this". I know that "self" is not a keyword while "this" is. And that is pretty much what I could figure out. Am I missing anything else? About self in Python (here is the source: Python self explanation ): The reason you need to use self . is because Python does not use the @ syntax to refer to instance attributes. Python decided to do methods in a way that makes the instance to which the method belongs be passed automatically,

This question already has an answer here: When to use `self.foo` instead of `foo` in Ruby methods 3 answers When do you use self.property_name in Ruby? Use self when calling a class's mutator. For example, this won't work: class Foo attr_writer :bar def do_something bar = 2 end end The problem is that 'bar = 2' creates a local variable named 'bar', rather than calling the method 'bar=' which was created by attr_writer. However, a little self will fix it: class Foo attr_writer :bar def do_something self.bar = 2 end end self.bar = 2 calls the method bar= , as desired. You may also use self to